Dental chair



(No MoqeL 5A sheetssheet 1.

" M. C. MERKER.

DENTAL HAR.

No. 605,255. Patented June 7,1898.

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5 Sheets-Sheet 2.

(No Model.)

M.C.MERKBR.

DENTALv GHAIR. y

I Patented June '7, 1898.

(No ModeLj 5 Sheets-Sheet 3.

M. C. MBRKER.

DENTAL CHAIR. No. 605,255. Patented June 7, l898l.`

(No Model.) 5 sheetssheet 4.

" M.. C. MERKER.

DENTAL CHA-IR.

PatentedJune'n chair.

` l Nrlrnn STATES' Prcn.

DENTAL CHAIR.

sPEcIFIcAT'IoN forming part or Letters Patent No. 605,255, dated June 7, 1898.

Application inea April 23,1897.;

To @ZZ whom. t may concern,.- l Y Be it known that I, MONT C. MERKER, a resident of Philadelphia,-in the 'county of Philadelphia and State of Pennsylvania,` have invented certain new'and usefulImp'rovements in Dental Chairs; and I do hereby declare the following to be a full,'clear7 and ex!u act description of the invention, `such as will enable others-` skilled in the art to'which it pertains to make and use the same.l 1

The invention relates to dental chairs, and has for its object to increase their efficiency and their ease, smoothness, and certainty of operation and to `simplify their construction and cheapen their cost so far as consisten with the first-named objects. l

The invention consists in the construction hereinafter described` and particularly pointed out. l l V In the accompanying drawings, Figure 1 is a partial central vertical section'of the base, pedestal, and seat-elevatingmechanism of a' Fig. 2 is a horizontal `section on line 2 2 of Fig. 1. Fig. 3 is a partial verticals'ection, showing pump-'operating levers. Fig. l is a side elevation, on a larger scale, of two of the said levers. Fig. 5 is asection on line 5 5 of Fig. 4. Fig. 6 is asection of a block containing antifriction-balls. Fig.7 is a section on line 7 7 of Fig. 6. Fig. 8 is a perspective of a lining for the ball-channel. Fig. 9 is a perspective'of a head-rest. Fig. 10 is a partial view of the same on an enlarged scale, several parts being shown as split and separated. Fig. 11 is a longitudinal section of the same parts assembled. Fig. 12 is a perspective of a seat-frame with attached foot-rest frame and a supplemental seat and frame. Fig. 13 is a section on line 13 13 of Fig. 2. Fig. 14 is an isommetric broken view of levers. Fig. 15 is a section showing a modied arrangement of antifriction-balls. Fig. 16 is an elevation of a pump-operating lever. Fig. 17 is an enlarged detail oa childs foot-rest. .l

Numeral 1 denotes the base, -and 2 the pedestal,- of a dental chair.

3 indicates an "oil-reservoir formed by the ilan ge 3 of the base, ande pumps having each the usual inlet-valve 5 and outlet-valve 5.

7 are passages in the casting 13 by which the pumps communicate with tube 8, iXed in the said casting, seated in reservoir bottom or base.' The casting 13 has a seat 13J in the base andlis fixed to the pedestal by a screw or." screws 13". A screw-plug having Vin its top a socket to receive loosely the stem of the valve 5 is denoted by 5X. The valve is normally closed by a spring 5". The removable socketed screw-pl ug normally holds the valve uprightand in operative relation to its seat and, also provides for its introduction or removal. For these'purposes it is situated immediatelyV under the valve and valve-seat and in the bottom of a detachable part, and the`pluglopeni'ng is of greater diameter than the valve to provide for the introduction of the latter. The socket in the plug is closed to prevent escape of oil.

6 indicates outlets for lowering the chair in usual manner.

. 9 denotes an extension-tube sliding on tube 8, and 10 and 10 are packings. A tube 11 is connected to a seat-frame 12. to engage each other when the tubes are rel` atively'moved to the` end of their paths are denoted by 14:.'`

. 15 is a movable extension-tube situated between the pedestal and tube 11. This pedestal extension-tube 15 has at its upper and lower ends a wall made sui'iiciently thick to permit forming therein continuous channels 16for `the reception of antifriction-balls 16. In somecases a block 17, provided with such channel, can be fixed in the wall of the tube, as shown in Fig. 13. The portion of the bottom of the channels that receives the most wear from the balls has alining 1S (see Figs. 7 and 8) of chilled steel or of a specially hard alloy or metal to obviate wear, cast-iron or brass being too easily worn.' This channel and lining are made concave, as indicated in said figures, to conform transversely to the balls,which are freely movable lengthwise of the continuous channels. The lower balls bear upon a stiff steel rib or plate 19, adjustably supported by the screws 20, passing through threaded openings in the pedestal projections 21 and,\if desired, `through the projections 22 in the reservoir. These plates and groups of friction-balls may be varied in number'- as desired.

In Fig. 2 are shown two upper series of balls bearing on plates 19 and a double series bearing on a plate 19' of double Width, the

Stops adapted object of this being to prevent independent rotation of the pedestal extension 15. Intermediate the several series of balls described are similar antifriction devices situated in tube 15 and having balls bearing on tube 11. At one point the series of balls is doubled, and the extension-tube 11 also has a flattened portion 11', made suiiiciently wide to serve as a bearing for the two rows of balls, as shown, the purpose being to obviate independent horizontal rotation of said tubes 11 and 15.

Instead of employing distinct sets of balls at the top and bottom of the tube 15 a continuous channel may be formed extending nearly the whole length of the tube and holding a single continuous series of balls arranged at its upper end to bear on the tube 15 and at its lower end to bear 011 a plate 19. Such construction is indicated in Fig. 13.

' An extension-tube situated between the pedestal and a plunger-tube, each of the latter being provided with ahntifriction devices, requires that the walls of both the pedestal and the plunger-tube be made thick to provide suitable space and support for said devices. It is characteristic of the present improvement that the channels for the balls are situated entirely in the pedestal extension, which alone need bev made thick to provide space for them.

Where the antifriction-balls or equivalent devices are arranged in one set, substantially as shown in Fig. 15, the bottom ones when lowered will descendinto the oil-reservoir and be lubricated by the oil therein and will by their movement lengthwise of their containin g-channel and by the movement of the pedestal extension carry oil to lubricate the tube 11 and the plates or Vtracks connected with the pedestal, Aagainst which tube and tracks the antifriction-balls bear at points above the reservoir.

In raising the chair-seat oil is forced into tube 8 and thence into tube 9 and through tube 9 into tube 11, supporting the seat-frame. This operation while continued pushes up the telescoping tubes and the seat frame, the movement of the tubes being limited, respectively, bystops 1 4 on the tubes and a shoulder 14 on the pedestal extension. Thus the ascent of tube 9, if sufficiently continued, will cause the stop at its foot to engage the foot of tube 11 or the stop thereon and the ascent of tube 11 will bring the stop at its foot against the shoulder 14' of the pedestal extension. When tube 9 descends, the stop 14 near its top may engage the stop 14 on-the foot of tube'- 11 and thus prevent their entire separation. The tubes 9 and 1l having been extended as stated, the frame can be raised still further by the exterior part of the stop -or flange 14 en-4 gagin g a shoulder on the interior of the pedestal extension 15, whereupon the tubes and extension may ascend together until the stop at the foot of the pedestal extension engages the-top of the pedestal. To reverse the movement and lower the chair, a valve-cock of any 4 each ring and the oil-displacer. v 4placing plunger partially ills the several usual or preferred form. is opened to permit the oil to escape from the tubes 8, 9, and 11 through outlets 6.

Into asocket in the closed end of tube 11 is screwed an oil-displacing plunger 13X, terminating in an approximately conical point at or near the level of the'bottom of the tube 11 and within the fixed tube S.

The packings 10 and 10 may be supportedin screw-rings 10, screwed into the top of the tubes, an annular space being left between This oil-distubes and occupies the space which would otherwise be lled With oil. The rod or plunger 13 is elevated simultaneously with tube 11 and its displacing effect in horizontal direction is maintained in said tube and in tube 9 at every point of their elevation. Less oil is required to ll them than would otherwise be the case and less time is therefore required to lill or empty them. By this means the quantity of oil in the several tubes is more nearly equalized and the rate of the ascent of the several tubes and the rate of their descent also is equalized. While more power is required to raise the seat at the same speed, owing .to the diminution of the transverse area of the oil in the cylinders, and especially in the larger ones, provision is made for this by the compound levers herein described, which levers,thou gh arranged within the small space available for the purpose, enable greater power to be exerted than otherwise practicable.

The pumps are operated by a compound lever comprising the sublevers constructed and operating as described below.

23 denotes a T-lever having a fulcruln at 24 in the swell or'lateral enlargement 24 of the pedestal. laterally for a pump or pumps between the pedestal and its extension and also for the oscillation of the lever 23. In the absence of this special enlargement of the pedestal neither of these devices could be placed between the pedestal and extension without a very considerable enlargement of the entire pedestal, and the special provision to avoid this is made as indicated in Figs. 2, 3, and 13. The T-lever is situated closely adjacent the relatively wide side 24, approximately tangential to the main part of the wall of the pedestal and connected by a, narrow side 24 to said main cylindrical part. This special form is employed to provide a suitable space for the oscillating T-lever and the piston-rods of the two pumps without unduly enlarging the main partof the pedestal. By this construction the lever can have its fulcrum in the pedestal and move parallel and closely adjacent the side 24, as indicated in Figs. 2 and 13, the pumps being arranged obliquely with respect to the radial lines of the pedestal and in the plane of the lever.

The arms of the T-lever arepivoted to pump piston-rods at 25 and 25'. To the foot of the Soy This enlargement provides space IIO 4its fulcrum, outside the pedestal, is iixed the pedal-crank 31. The short arm of the lever 29 has a slot 29', in which is normally held the pin 28. 4

To operate the pump in raising the chairseat, the pedal-crank 31 is depressed, with the effect totnrn the lever 29 on its fulcrum, which lever by its slotted end applied to the pin 28 rotates the lever 26 about its fulcrum 27 and moves the lever 23 about its fulcrum 24, with the eifect to operate the pump-pistons. The pin 28 moves freely in the slot 29' during this operation, as also does the pin 23', held in an oblong slot formed in the foot of v the T-.lever 23. The described arrangement and combination of levers provides for assembling them in a smaller compass vertically, and the long arm of the main lever 23 can be extended nearer the base and the power very much increased.

A frame for the support of a supplemental seat and foot-rest suitable for children is denoted by 32. This is connected to the chairseat frame by pivots 33, having suitable bearings in the lugs 34, cast on the frame.

35 denotes an extension of the seat-frame, which maybe styled the foot-rest frame. The frame 32 is similar in form to frame 35, though smaller, and when turned down is situated between the side bars of saidgframe 35. It may be supported by ledges or lugs 36, situated on the inside of said bars. The childs seat or its frame may when turned down engage with a cross-bar or lug 37 on the main foot-rest frame.

39 denotes an upholstered childs seat. (Shown in operative position in Fig. 12.)

By this construction a childs seat and its frame can be normally held within the main foot-rest frame and serve as a platform and when desired for use can be swung'up` into a convenient and operative relation to the headrest, a practical result which has been much desired.

40 denotes a supplementary or childs footrest having at 41 pivoted connection with the frame 32. Stops to limit the movement of the foot-rest 40 and retain it in' an approximately horizontal position are denoted by 42. Vhen frame 32 is turned down to an inoperative position, the foot-rest 40 is folded up against it by contact with the main foot-rest frame or with ledges or lugs 37 thereon.

60 denotes a detachable arm-rest provided with a screw-threaded stem 61, adapted to be screwed either into the hole 62 in the main seat-frameor into the hole 63 of the childs seat. Such rest can of course be used on either side of the seats.

44 denotes the ball of a universal joint such as commonly used to support head-rests. Said ball has an` arm 43, provided witha ring l 45, having an angular opening, as indicated, to fit and move on a similarly-shapedpart 46 of a short rod 47. Said rod is screw-threaded ateach end and on the lower end is squared to receive a laterally toothed or serrated ring 48, which is held in place by a jam-nut 49. A rotatable hand-wheel having a screw-thread connection with rod 47 is denoted by 50.. 60 denotes a washer having a key 62 to enter a slot 61 to prevent friction between the wheelliuband anarm-ring below. Upon the rod between this ring 48 and the wheel 5D are held four arms 52 53 58 58, having rings 51 integral therewith,rotatably supported on unthreaded portions of the rod, the middle `rings 51 being in contact ywith ring 45. Two of these arms (denoted by 52 and 53) are pivotally connected each` to the inner lower end of a pad or pad-support 54. The ring 51 of the arm 53 is provided with teeth 55 or the like, adapted to engage with similar teeth onthe .ring 48 to securely lock these parts together when they are properly engaged for the purpose by suitably turning the wheel 50.

Whenever itis desired to adjust the arms about their support to adapt the pads to fit the back hair of a female patient, for example, the Wheel-nut should be unscrewed sufficiently to permit the several rings to have the necessary movement lengthwise of the supporting-rod 47, whereby they are loosened or unlocked to permit sufficient rotation. The wheel-n ut is ordinarily kept loose enough so that the teeth at 55 may be disengaged by` pressing the pads toward each other. These teeth are made fine to facilitate the turning of the ring pertaining to arm 53. The upper roo two of the four arms above referred to are indicated by 58. At 57 these are pivotally connected each with a limb 59.

The construction provides for several adjustments of each pad either bythe occupant of the chair or by others. For example, the arm 53 being heldby the hand against rotation the corresponding arm 59 can be rotated about 57 to change the inclination of the pad by moving its upper or outer part. An arm 58 being held in like manner the arm 53 can be rotated and the pad tilted by a suitable movement of its lower part, the upper part remaining nearly stationary. Thus if it be desired to change the inclination of the pad without materially changing the elevation of its upper end, then an arm-as 53, for examcase the manipulation of the arms does `not bind'zthem togethersufliciently to maintain IIO their position by the operation of the inclined surfaces of the arm-rings, (indicated in Figs.

- 9 and 10,) then the parts can be tightened by the wheel-nut.

Obviously mere mechanical changes can be made in the several devices described herein Without materially affecting their principles of construction and operation, and I do not wish to be limited to the use of the T-lever or of a particular number of tubes or of antifriction devices or t0 other details except as pointed out.

I-Iaving described my invention, what I claim is- 1. The combination of the pedestal,the tube 11 having a flattened exterior surface to provide a bearing for two laterally-adjacent series of balls, and the pedestal extension-tube, said pedestal extension-tube having channels provided with antifriction-balls adapted to bear on the tube 11 and mediately on the pedestal, substantially as described.

2. The combination of the pedestal,the tube 11, and the pedestal extension-tube, said latter tube having channels provided with antifriction-balls adapted to bear on said tube l1 and mediately on the pedestal, and with adjustable bearing-plates for the balls intermediate the pedestal and its movable extension, substantially as described.

3. The combination of the pedestal,the tube l1, and the pedestal extension-tube, said latter tube having channels provided with antifriction-balls adapted to bear on tube 11 and mediately on the pedestal, and with adjustable bearing-plates for the balls intermediate the pedestal and its movable extension, one of the plates being made wide. to furnish a bearing for two laterally-adjacent series of balls, substantially as described.

4. The combination of the pedestal provided with interior tracks for antifriction devices, the seat-tube 11 supporting the chairseat,the pedestal extension-tube intermediate the pedestal and seat-tube, antifriction-balls carried by said pedestal extension, said balls situated near the top and bottom of the extension-tube being oppositely situated and bearing respectively on tube 11 and on the pedestal-tracks, and the oil-reservoir situated in the path of the extension-tube, substantially as described.

5. In a dental chair, the combination of tubes to hold a liquid column for the raising and lowering ot' a seat, a pump to force liquid into said tubes, a lever having'a fulcrum supported by the pedestal and connected to the pump-piston, a lever having a t'ulcrum in the pedestal-wall with one arm extended outside thereof and provided with an operating-crank, the other arm of said lever being situated within the pedestal and slotted, a lever having a fulcrum in the pedestal-wall below and adjacent the slotted lever and provided with a pin situated in the slot of said slotted lever the arm of said lever with a pin being extended below its pin and loosely conl nected to thetirst-named lever, substantially as described.

` 6. In a dental chair, a supplemental seatframe pivoted to the main seat-frame and adapted to support a supplemental seat above rest frame, a supplemental foot-rest pivoted to the supplemental seat-frame,said supplemental foot-rest being adapted to be folded when the supplemental seat-frame is turned down and between the two frames, substantially as described.

9. A dental chair having a main seat-frame and a supplemental seat-trame, a detachable arm-rest, said rest and frames being provided with means whereby the rest Vmay be connected to either seat-frame, substantially as described.

l0. In a head-rest support, the ball of the ball-and-socket jointv provided with an arm and ring the latter having an angular opening, the rod provided with an angular part intermediate its ends to movably fit the said angular opening, pad-supports having rings embracing said rod, and means for locking said rings together, the ball-arm ring being situated between said locking-rings,substantially as described.

1 1. In a head-rest the head-supporting pads provided with several arms movably held on a rod and the arm extending from the ballot' a ball-and-socket joint, said rod and arm being rigidly connected circumferentially and loosely connected lengthwise the rod at a point near its center and means for fastening the arms together, substantially as described.

12.v In a dental chair, the combination of the approximately cylindrical pedestal provided with a lateral enlargement 24: having relatively long and shortsides 24C and 24', one side being approximately tangential to the main body of the pedestal-wall, the pumps situated partly in the recess formed in the enlargement and adjacent said latter side, and the two-armed lever having a fulcrurn in said side and movable parallel therewith, substantially as described.

13. The combination of telescoping tubes and means for moving a tube or tubes by fluidpressure to extend them with a device for displacing a part of the iiuid in the larger tube or tubes, substantially as described.

14. The combination of telescoping tubes and means for moving a tube or tubes by iiuidpressure to extend them with a device for dis- IOO IIO

placing a part of the iiuid in a larger tube or tubes, said device being attached to and movable with a tube, substantially as described.

15.` The combination With telescoping tubes and means for moving a tube or tubes by fluidpressure to extend them of a duid-displacing plunger situated in thelarger tube, said means for producing the pressure comprising one or more pumps and a compound lever to operate the same, substantially as described.

16. In combination the base having a flange 3 constituting with said base an oil-reservoir and having integral with its bottom an annular closed seat 13', the castingl rotatable in said seat and having pump-ports, a pump and tube 8 supported in said casting and the latter having an extension ixed to the pedestal whereby the casting supports the tube and pumps and moves With the pedestal, substantially as described.

17. The compound lever having a pivoted member 29, and a pivoted member 26, said members being loosely connected and each provided with a separate pivot or fulcrum, and a lever 23 having a fulcrum 24 and loosely connected to the lever 26Vintermediate said levers 23 and 2,9, substantially as described.

1S. In combination with a separable casting having an opening in its bottom and interior conduits, with inlet and outlet valve seats for a pump-cylinder, one of said seats being immediately over the said opening, an upwardlyclosing valve provided with a stem and a removable plug having a larger diameter thanV ing Witnesses.

MONT C. MERKER. Witnesses:

WM. W. STEWART, E. H. WARBONE. 

